Mikael Lustig has admitted the mental torture of his injury nightmares almost broke him.

But the Swede has stayed strong. And Celtic’s forgotten star has vowed to return better than ever as he feels he owes the club for standing by him in his time of need.

Lustig missed the last three and a half months of the campaign and participating on the trophy-winning days in the League Cup and Premiership after sustaining a serious ankle injury.

The defender’s misery came on top of missing a large part of last season with hip problems and he has also been dogged by a groin injury.

Deep down, the 28-year-old believes he has been denied the chance to display his best form for the Scottish champions.

Worse than that, it almost makes him feel like he’s been stealing a living.

Lustig can’t stand being out. Can’t stand the thought of picking up his wages without contributing.

At times, the anguish was close to wearing him down as he said: “When you have a contract you want to be giving something back to the club.

“I’ve been out for almost a year if you add all the injuries up and it’s not that great.

“You get paid by the club for, in my eyes, doing nothing.

“I can’t stand that. I want to be part of it all of the time and it’s hard when you’re not.

“When you’re not playing it’s so frustrating. Mentally, it’s been really hard.

“Some of the weeks have been okay but some of the weeks when I have been sitting on an exercise bike for hours at a time, I’ve felt like, ‘What am I doing here?’

“It feels like that sometimes and you feel as though you are getting nowhere.

“In the past couple of weeks I felt better getting outside and being part of some of the passing exercises. But it’s been a hard time, absolutely.

“Over the last two seasons I’ve missed far too many games. Every time you get injured and have a long lay-off you promise yourself that you won’t come back and break down.

“This injury was a little bit different because I didn’t break down over an old one, it was new, it was unlucky and could have happened to anyone.

“When I had the hip operation last season it was no fun sitting there every day watching the lads go out to play.

Mikael Lustig (Photo: SNS)

“This season it has happened again and I can’t believe it.

“When I got back I was feeling really good. I actually thought that this was going to one of my best seasons for the club.

“I was so excited about what could happen, then something else happened. When I came back I wasn’t up to 100 per cent sharpness but my confidence was high and I felt as though I was playing well.

“Sometimes you feel as though you are being denied some of your career through bad luck.

“I know that injuries are part of the game and everyone will get them. Sometimes you can be smarter. Like when you have a hamstring injury or something, you perhaps should not play but this ankle injury was different.

“The physio and the doctor said it might be three weeks or it might be four months.

“When you hear that and it turns out to be the longest one, it’s mentally hard to take.

“You hope it will take less but it hasn’t happened.

“It’s nice to play football because when you’re angry with things in life you can take it out during a game.

“I feel the gaffer has faith in me and obviously he wants me fit, so that makes me determined.”

While the rest of his team-mates have jetted off to sunny climes for a well-earned break, Lustig is getting down to even more serious work.

For beach read treadmills as the full-back steps up his rehabilitation.

Although he’ll take his family away, Lustig has a training programme drawn up to get him back to where he feels he needs to be to assist Deila, the Daily Record reports.

He said: “I’m going to take some time off but I know I’m a long way from my physical limit and I’ll have to work harder than the other guys.

“The lads who have played all season need to relax for three or four weeks but I can’t do that.

“I have to keep working and I’ll be doing a little something every day to keep building up and working back.” Naturally, Lustig has targeted the Champions League qualifiers for a comeback. The importance of the matches are ingrained into the squad psyche and Deila has plotted his pre-season schedule around making it through to the group stages.

Lustig is desperate to be involved. But although he’s on schedule he admits he’s not going to risk another long-term injury by taking any chances.

Lustig said: “I have to be careful. When you spend time at Celtic you come to realise that July and August are becoming almost the important months of the entire year.

“Of course I want to be ready for that and I am going to try my best. But I also know that it is a long season and the last thing I want to do is get back, play a couple of games and then be out for another long while.

“I’m desperate to be back and playing.

“I want to get back every day training with the lads but you have to be smart.”